Buffalo!
My new favorite sentence in the English language:
Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo.
It's a grammatically correct sentence that utilizes three different meanings of the word "buffalo": one as an adjective, one as a noun, and one as a verb. Pay close attention to the capitalization!
It sort of makes you appreciate the difficulty of learning English (or any language, for that matter).
Hence, the fanatical devotion of fans of Crazy English, maybe? From the New Yorker article about Li Yang's shouting-as-learning program:
Li's cosmology ties the ability to speak English to personal strength, and personal strength to national power. It's a combination that produces intense, sometimes desperate adoration. A student named Feng Tao told me that on one occasion, realizing that he had enough cash for tuition to an out-of-town Li lecture but not enough for train fare, "I went and sold blood."